1. Technical Field
The embodiment described herein relates to a semiconductor memory apparatus and, more particularly, to a circuit for compensating temperature detection range of a semiconductor memory apparatus.
2. Related Art
In general, a temperature measurement circuit of a semiconductor memory apparatus measures temperature by using an oscillator signal with a frequency that does not vary regardless of variation in temperature and a pulse having a pulse width that varies depending on the variation in temperature. At this time, by using the pulse having the pulse width that varies depending on the variation in temperature as an enable signal of a counter and counting the oscillator signal while the counter is enabled, temperature information is encoded and outputted.
As such, the temperature measurement circuit in which the counter is enabled by using the pulse as the enable signal and the enabled counter counts the oscillator signal has the following problems.
The counter counts the oscillator signal while the pulse is enabled, such that an output of the counter may be larger than the maximum value while the pulse is enabled. If a 4-bit counter has the maximum value (1,1,1,1), a subsequently counted output of the counter is (0,0,0,0).
As a result, the temperature measurement circuit in which an output value of the counter increases as the temperature increases cannot accurately measure the temperature because the counter reaches the maximum value and thereafter, decreases to the minimum value.